Pulling tool

ABSTRACT

An improved tool for pulling off a rotor of a motor from a shaft or a fan from a shaft, which improved tool is provided with hooked arms that are releasably but securely held at one end in the housing, without the use of retaining clips, so that the arms do not fall off during use or become lost, and so that they do not interfere with the use of the tool when using the securing bolts for pulling off a rotor. The housing of the improved tool of the invention is circular in shape, and in a first version, is provided with a plurality of equally-spaced holes about its circumference, which holes received the hooked ends of the hooked arms, so that various configurations of hooked arms may be provided to best suit the configuration of vanes and type of fan being pulled off a shaft. In another version, instead of the plurality of equally-spaced holes for holding the hooked ends of the hooked arms, an annular groove is provided on the upper, horizontal surface of the lower circular cross-sectioned section of the housing, which annular groove is preferably continuous for 360 degrees about the upper, horizontal surface of the lower circular cross-sectioned section of the housing, whereby there is provided substantially an infinite spacing capability to the hooked ends of the hooked arms.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation-in-part of application Ser.No. 08/061,362, filed on May 12, 1993, now U.S. Pat. No. 5,390,404,which is a continuation-in-part of application Ser. No. 07/900,348,filed on Jun. 18, 1992, now U.S. Pat. No. 5,211,211, which is acontinuation-in-part of application Ser. No. 07/737,046, filed on Jul.29, 1991, now U.S. Pat. No. 5,163,211.

BACKGROUND OF THE INVENTION

The present invention is directed to a tool for pulling off a rotor of amotor or a fan from a shaft. In U.S. Pat. No. 4,077,103--Kelley, whichis incorporated by reference herein, there is disclosed such a tool forpulling off a rotor of a motor or a fan from a shaft. The tool includesan elongated, rotatable screw that is partially threaded in a hollowhousing. The end of the elongated screw can be made to protrude from theend of the housing by rotating the screw in a first direction. Bycausing the end of the screw to protrude from the housing, the end maybe brought into abutting engagement with the end of a shaft on which ismounted a rotor of a squirrel-cage motor, for example, or a fan. Thehousing is provided with means for securing the housing to either therotor of a motor or to a fan, whereby, after abutting the end of theelongated screw against the end of the shaft, the screw is rotatedcausing the housing, with the securing means, to be translated along thescrew, in a direction away from the shaft, which housing thereby carriesalong with it the rotor of the motor or the fan on the shaft to whichthe securing means had been applied. The securing means takes the formof a plurality of rotatable gripping bolts that are used for grippingthe outer surface of a rotor of a motor, or the like, while, forremoving a fan, or the like, from a shaft, a plurality of hooked armsare provided with an end of each hooked arm being removably received ina hole of the housing, with the other end "hooking" a rearsurface-portion of the fan, whereby the respective rotor or fan, or thelike, may be pulled off the shaft according to the methodabove-described. However, the hooked arms of this patent suffer from theserious disadvantage of falling out from their insertion-hole in thehousing. Thus, the tool of the patent is also provided with retainingclips for holding the hooked arms in place, so they do not fall out andbecome lost, and so they do not interfere with the use of the securingbolts when pulling off a rotor of a motor, or the like, from a shaft.However, these retaining clips have not been found to be practicable inuse, and have been ineffective in preventing the hooked arms fromfalling out and from interfering with the securing bolts for a rotor ofa motor. In addition, the shape of the housing in the tool of the patentis square-shaped with the holes formed in the housing for receiving theends of the hooked arms being provided in two, adjacent pairs, where onepair of holes is formed in one lateral surface face of the housing, andthe other pair of holes in the opposite surface face of the housing.This arrangement fixes the manner in which the hooked arms are arrangedwith respect to the housing, which is a severe detriment to the use ofthe tool, since not all fans are provided with the same number of vanesnor with vanes of the same angular extent. Thus, where the hooked armsmay be perfectly suited for a fan with four blades, the tool can only beused with difficulty for fans having more or less than four vanes, or afan having vanes of considerably different angular extent.

SUMMARY OF THE INVENTION

The present invention is directed to an improved tool for pulling off arotor of a motor from a shaft or a fan from a shaft, which improved toolis provided with hooked arms that are releasably but securely held atone end in the housing, without the use of retaining clips, so that thearms do not fall off during use or become lost, and so that they do notinterfere with the use of the tool when using the securing bolts forpulling off a rotor. The hooked arms of the invention are alsohexagonal-shaped, and the securing bolts are provided withhexagonal-shaped recesses in their heads, so that the hooked arms maythemselves be used for rotating the securing bolts when pulling off arotor of a motor from a shaft. In addition, the housing of the improvedtool of the invention is circular in shape, and is provided with aplurality of equally-spaced holes about its circumference, which holesreceived the hooked ends of the hooked arms, so that variousconfigurations of hooked arms may be provided to best suit theconfiguration of vanes and type of fan being pulled off from a shaft. Toensure that the each hooked arm is releasably retained in a respectivehole of the housing, the end of the arm is provided with a hook definedby a straight piece extending at an acute angle with respect with themain, elongated body of the arm. Also provided are peep-holes forviewing into the interior of the housing, in order to ensure that theend of the screw is properly aligned with the end of a shaft when thetool is used for pulling off a work piece. In another version, insteadof the plurality of equally-spaced holes for holding the hooked ends ofthe hooked arms, an annular groove is provided on the upper, horizontalsurface of the lower circular cross-sectioned section of the housing,which annular groove is preferably continuous for 360 degrees about theupper, horizontal surface of the lower circular cross-sectioned sectionof the housing, whereby there is provided substantially an infinitespacing capability to the hooked ends of the hooked arms. Alternatively,the annular groove may be discontinuous so as to provide a plurality ofindividual, separated, smaller grooves, any one of which may receivetherein a hooked end of a hooked arm. In this modification, thesesmaller grooves are also preferably equally spaced about the upper,horizontal surface of the lower circular cross-sectioned section of thehousing, although their spacing may be staggered rather thanequally-spaced.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more readily understood with reference to theaccompanying drawing, wherein:

FIG. 1 is an isometric view of the pulling tool of the invention;

FIG. 2 is an isometric view thereof showing the tool in use for pullingoff a fan from a shaft;

FIG. 3 is a detail view, in partial cross section, showing the shape ofthe upper end of each hooked securing arm for releasable but securelymounting it in a hole of the housing of the tool of the invention;

FIG. 4 is a longitudinal cross-sectional view of the tool showing thehooked securing arms in use;

FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4;

FIG. 6 is a plan view showing the supplemental use of each hookedsecuring arm for rotating the securing bolts; and

FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 6;

FIG. 8 is a cross-sectional view of a modification of the pulling toolof the invention in which there is are provided sight-holes for viewingthe emplacement of the tool;

FIG. 9 is a top view thereof;

FIG. 10 is an isometric view of a modification of the pulling tool ofthe invention, in which a larger-diameter adapter-tube is attached tothe tool of FIG. 1 for pulling off extra-large components with thebolts;

FIG. 11 is a cross-sectional view taken along line 11--11 of FIG. 10;

FIG. 12 is a cross-sectional view taken along line 12--12 of FIG. 10;

FIG. 13 is a cross-sectional view of another modification of the tool ofFIG. 1, in which a smaller-diameter adapter-tube is attached to the toolof FIG. 1 for pulling off smaller-size components with the bolts;

FIG. 14 is a cross-sectional view taken along line 14--14 of FIG. 13;

FIG. 15 is a cross-sectional view taken along line 15--15 of FIG. 13;

FIG. 16 is an isometric view showing still another modification of theinvention where all of the first and second plurality of holes for thebolts and securing arms are contained in one plane near the bottom, openend of the housing;

FIG. 17 is an isometric view showing yet another modification of theinvention where an enlarged, circular disc is placed over thefrusto-conical section of the housing by which larger components may bepulled off with the securing arms;

FIG. 18 is an isometric view of another adapter-component that is usedto help brace a component being pulled off by the securing arms;

FIG. 19 is a cross-sectional view showing the adapter-component of FIG.18 in use.

FIG. 20 is an isometric view showing still another embodiment of thetool of the invention, where, instead of the plurality of equally-spacedholes for holding the hooked ends of the hooked arms, an annular grooveis provided on the upper, horizontal surface of the lower circularcross-sectioned section of the housing;

FIG. 21 is a longitudinal, cross-sectional view of the tool of FIG. 20;

FIG. 22 is an enlarged detail view, in partial cross section, showingthe connection of a hooked end of a hooked arm in the annular groove forretention thereby; and

FIG. 23 is an isometric view showing a modified form of the tool of FIG.20 where a plurality of annular grooves are provided.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in greater detail, the tool of theinvention is indicated generally by reference numeral 10. The toolincludes an elongated, rotatable screw 12 that is rotatably mounted in ahollow housing 14. The length of the screw 12 is greater than the lengthof the housing, so that the end 12' of the screw may be made to protrudeout of the enlarged open end 14' of the housing. The housing 14 isitself divided into a narrow-diameter portion 16, and an larger-diameterportion 18. The narrow-diameter portion prevents the screw 12 fromwobbling during use. The larger-diameter portion 18 mounts securingmeans which contact the element, such as a rotor of a motor or a fan,for pulling it off a shaft. The securing means has a first set of bolts20 that are rotatable in holes 22 formed in the housing which grip, attheir interior ends, the outer, circumferential surface of a rotor to bepulled off from a shaft. The securing means also has a series of hooked,securing arms 26 that are used for gripping a fan for pulling the fanoff from a shaft. Each securing arm has a main, elongated portion 26', afirst end 28 for passage through one of a plurality of holes 30 formedin the housing, and a second end 32 that "hooks" the fan from behind, inthe manner depicted in FIGS. 2 and 4. The above-described parts areconventional, as shown in U.S. Pat. No. 4,077,103--Kelley.

The tool 10, however, is a considerable improvement over the prior art,as described hereinbelow. Whereas the prior art housing was rectilinearin cross section, the larger-diameter housing portion 18 is circular incross section, with the holes 30 equally spaced thereabout. The numberof holes is preferably six in number. This arrangement of the holes 30allows for the securing arms 26 to be equally-spaced apart which bettermatches the vanes of a fan to be pulled off, and also allows fordifferent arrangements. For example, when a fan with only three vanes isto be pulled off, only three securing arms 26 need be used, which threeare inserted into every other hole 30 to better match the configurationof the fan to be removed. The arrangement of holes 30 allow for otherarrangements of the securing arms 26 that suit the particular fan, orsimilar device, to be pulled off, providing a much more adaptable andflexible tool to suit various types of jobs and environments.

Each securing arm has a first, hooked end 28 made up of a first,substantially-horizontal section 28' and a second, angular section 28".The angular section 28" forms an acute angle with respect to thevertical, center line of the main elongated portion 26' of the securingarm. In the preferred embodiment, this acute angle is between 30 and 60degrees with respect to the vertical, when viewing FIG. 3. Thisacute-angle section 28" with horizontal section 28' allows for insertionof the first end of the securing arm through a hole 30 in a relativelyeasy manner, and yet prevents the accidental removal of the first endfrom the housing 14. The straight, horizontal section 28' acts as afulcrum, and ensures that the main elongated portion 26' of the securingarm is allowed to hang downwardly as close to vertical as possible, andprovide enough leeway, so that the second end of the securing arm may be"hooked" about the back of a fan, or the like to be pulled off from ashaft, such leeway also resulting from the acute-angle section 28" andits contact against the interior wall surface adjacent the respectivehole 30, which provides a fulcrum for rotation a direction perpendicularto the rotation allowed by the horizontal section 28' whereby thesecuring arm may be rotated to a limited enough degree for entrainingthe second hooked end of the securing arm in back of the fan forgripping it, if necessary. Each hole 30 has a diameter larger than thediameter of the securing arm, so as to also provide the necessary leewayto the first end 28' of the securing arm to ensure the limited pivotingof the first end 28' about the fulcrum provided by the acute-anglesection 28".

Each securing arm 26 of the invention has an hexagonal cross-sectionalshape, as seen in FIG. 7. The reason for this is to allow the use ofeach securing arm for rotating the securing bolts 20. Each bolt has ahex-head portion 40 that may be gripped by a conventional wrench forrotating the bolt, and also has, according to the invention, ahexagonal-shaped recess 42 which receives the hexagonally-shaped end 32'of the second end 32 of a securing arm, whereby the securing arm may beused as a driver for rotating the bolt. Since, when the bolts 20 areused for pulling off a rotor of a motor, the securing arms 26 are notneeded, the present invention allows for a dual-function for thesecuring arms. The other arms 26 not being used to rotate the bolts 20are prevented from falling out during their nonuse period by theacute-angle section 28" above-described, and also are prevented frominterfering with the bolts 20, since they cannot accidentally fall out,and since they only have a very limited capability of angular pivotingin a direction where the second end 32 moves toward the housing portion18.

Referring to FIGS. 7 and 8, there is shown a modification 70 of thetool. The pulling tool 70 is substantially identical to the tool 10,except for the additions of a plurality of peep-holes or sight holes 72.The holes 72 are placed on the frusto-conical section 74 of the housingsection 76. As seen in FIG. 9, two such holes 72 are provided, spaced180 degrees apart, although more or less than two may be used. When morethan two are provided, the holes would also be spaced equidistantlyapart. The peep-holes provide a line-of-sight to the interior of thehousing 76 when the tool 70 is being put in place. Without the provisionof the peep-holes 72, it sometimes may occur that the end 78 of thescrew 80 may not placed directly against the end of the shaft, or thelike, but against a different portion, without the user of the toolbeing aware of it. By providing the peep-holes 72, the user may gazedirectly into the interior of the housing section 76, and see directlyif the end 78 of the screw 80 is in proper, abutting contact against theend of the shaft. Owing to the frusto-conical shape of the housingsection 74, the surface thereof slopes upwardly to meet at a commonarea. Therefore, the lines of sight provided by each peep-hole 72intersect the lines of sight provided by the other peep-holes 72, whereat least some line-of-sight provided by each peephole 72 intersects theend 78 of the screw when the end is extended into its operativeengagement with a shaft-end. The holes 72 are made large enough, sothat, for all extensions of the screw-end 78, there is a line-of-sightprovided thereto. By virtue of the fact that the peep-holes 72 areprovided on the frusto-conical section 74, the required size thereof isreduced, since the sloping surfaces of the frusto-conical section 74naturally direct the lines-of-sight toward the end 78 of the screw,whereby the structural integrity of the housing proper is lesscompromised. The peep-holes 72 are also preferably placed high enoughalong the sloping surface of the frusto-conical section 74 so that therequired lines-of-sight clear the hooked ends 28 of the securing arms 26described above, which project into the interior of the housing 74through the equally-spaced holes 30 seen in FIG. 1. Thus, preferably,each peep-hole 72 is placed above and arcuately between two adjacentholes 30 rather than being aligned with any one of them, although, ofcourse, the alignment thereof may be provided, as long as the peep-holes72 are large enough in order to provide the proper lines-of-sight.

Referring to FIGS. 10-12, there is shown a modification 90 in which anadapter-tube or component 92 is capable of removable assembly with thetool. The adapter-tube 92 is circular in cross section, and has alarger, inner diameter than the outer diameter of the larger, circularsection 18 of the housing of the tool. The adapter-tube 92 has a firstplurality of holes 94 that allow some of these holes 94 to align withall of the lower plurality of holes 22 of the tool proper, so that eachaligned pair of holes 94-22 may receive therethrough a bolt, like thebolts 40, for fastening the adapter-tube 92 to the housing 18, as seenin FIG. 10. As seen in FIGS. 11 and 12, there is, preferably, providedsix such holes 94, in order to be able to secure the adapter-tube 92 toa housing having either three or four holes 22 spaced equidistantlyabout the lower end of the housing 18 of the tool. Thus, four holes 94'are spaced 90 degrees apart, while two holes 94" are spaced 120 degreesapart. In FIG. 11, the adapter-tube 92 is shown secured to a tool havingjust three holes 22 for the bolts 20. The adapter-tube 92 also has alower plurality of holes 96, which are preferably four in number, whichholes 96 receive therein bolts 98, like the bolts 20, for attaching theadapter-tube 92, and, therefore, the entire tool, to a larger-diameterrotor, or other larger-diameter component that is to be pulled off, inthe same manner as the bolts 20 are used in the embodiment of FIG. 1.

Referring to FIGS. 13-15, there is shown another modification 100 inwhich a smaller-diameter adapter-tube or component 102 is capable ofremovable assembly with the tool. The adapter-tube 102 is circular incross section, and has a smaller, outer diameter than the inner diameterof the larger, circular section of the housing 18 of the tool. Theadapter-tube 102 has a first plurality of holes 104 that allow some ofthese holes 104 to align with all of the lower plurality of holes 22 ofthe tool proper, so that each aligned pair of holes 104-22 may receivetherethrough a bolt like the bolts 20, for fastening the adapter-tube102 to the housing 18, as seen in FIG. 13. As seen in FIGS. 14 and 15,there is preferably provided six such holes 104, in order to be able tosecure the adapter-tube 102 to a housing having either three or fourholes 22 spaced equidistantly about the lower end of the housing 18 ofthe tool. Thus, four holes 104' are spaced 90 degrees apart, while twoholes 104" are spaced 120 degrees apart. In FIG. 15, the adapter-tube102 is shown secured to a tool having just three holes 22 for the bolts20. The adapter-tube 102 has a lower plurality of holes 106, which arepreferably four in number, which holes 106 receive therein bolts 108,like the bolts 20, for attaching the adapter-tube 102, and, therefore,the entire tool, to a smaller-diameter rotor, or other smaller-diametercomponent that is to be pulled off, in the same manner as the bolts 20are used in the embodiment of FIG. 1.

In each modification 90 or 100, when the respective adapter-plate isattached, the securing arms associated with the tool may, under certaincircumstances, be used in the holes 96 or 106, respectively, instead ofthe bolts therefor, although the primary function of these adapter-tubesare for the bolts for pulling off rotors.

Referring to FIG. 16, there is shown yet another modification 120 inwhich all of the first and second plurality of holes 22, 30 of theembodiment of FIG. 1 are contained, or located, in substantially oneplane, or level, near the open end of the housing. Thus, in themodification 120, a first plurality of holes 122 for the bolts 120 arethree in number, and a second plurality of holes 130 for the securingarms 126 are six in number. The holes 122 are spaced equidistantly apartabout the lower end of the circular part 118 of the housing of the tool,which constitutes 120 degrees of arcuate separation. The holes 130 arealso spaced equidistantly apart about the lower end of the circular part118 of the housing of the tool, which constitutes 60 degrees ofseparation. Moreover, each hole 122 is sandwiched between, or flanked,by two holes 130, where each hole 130 is, also, separated from another,adjacent hole 130 by one hole 122, as can be seen, in FIG. 16.

Referring to FIG. 17, there is shown yet another modification 140 inwhich the tool of FIG. 1 is provided with a larger-diameter disc orplate 142. The plate 142 has a central opening 142' which is smallerthan the largest-diameter section of the frusto-conical portion 28", butlarger than the smallest-diameter section of the frusto-conical portion28", so that the plate may be removable supported on the frusto-conicalportion 28", as seen in FIG. 17. The plate 142 has a plurality ofequally-spaced holes 144, which form a circular array of holes about thecenter of the opening 142'. The radius of this circular array, asmeasured form the center of the opening 142' to the inner-most radialsections of the holes 144, is greater than the outer diameter of thelarger, circular section 18 of the housing of the tool, so that thehooked ends of the securing arms 146 may be inserted in chosen ones ofthe holes 144, for pulling off larger-diameter components. As shown inFIG. 17, 14 such holes 144 are provided, whereby three or four, or evenmore than four, securing arms may be inserted into selected ones of theholes 144, which selected holes are those best suited to the specific,larger-size component being pulled off. The securing arms 146 are thesame as the arms 26 of FIG. 2, and are used in the same manner. In orderto ensure that the plate 142 is supported firmly and equally about itsentire periphery, the frusto-conical section 28" may be provided with anintermediate, annular, flat stepped-portion upon which the plate 142rests. In a version of the tool 10 where there is no frusto-conicalsection 28", but just the sudden, flat, stepped transition from thesmaller-diameter housing-portion 16 to the larger-diameter section 18,then the plate 142 will rest directly upon this transition step.

Referring to FIGS. 18 and 19, there is shown a reinforcing ring 150 thatmay be used with any of the above-described embodiments. The ring 150 ispreferably circular in shape, although such is not a prerequisite, andhas an opening, or gap, 152 in it. The reinforcing ring 150 is used whenthe securing arms pull off a fan, or the like. Since the forces createdin the hub of the fan when the securing arms are pulling the fan off areextremely large, there is a possibility that the bending moments createdon the hub will harm or warp the hub, preventing its further use, orwill impede the process of removal. By placing the reinforcing ring 150between the hub of the fan (shown in dotted lines in FIG. 19) and thegripping-ends of the securing arms, the forces are distributed over amuch larger surface-area, thereby preventing damage to the hub of thefan. Preferably, the diameter of the ring 150 is greater than thediameter of the hub being pulled off so that no portion of the hub iscontacted by the securing arms. The gap 152 allows the ring 150 toclear, or pass therethrough, the shaft of the hub of the fan, so thatthe ring may be emplaced against the hub, as seen in FIG. 19.

Referring to FIGS. 20-22, there is shown an other embodiment 200 of thetool of the invention. In this version, instead of using a plurality ofequally-spaced holes for holding the hooked ends of the hooked arms, anannular groove or depression is provided instead, as describedhereinbelow. The tool 200 has a main housing 202 consisting of a first,narrower section 204, and a second, larger-diameter section 206, which,as shown, is preferably circular in cross section, although other,noncircular cross sections may be used. In this version, thelarger-diameter section 206 is not connected to the upper section 204 bymeans of a frustoconical section, but is connected to it directly, asseen in FIGS. 20 and 21, to define an upper, annular, stepped horizontalflat surface 210. In this upper, annular, stepped horizontal flatsurface 210, there is provided an annular groove or well 212, which, inthe preferred embodiment, is continuous and extends a full 360 degreesabout the upper flat surface 210. The annular groove 212 has a depth, asbest seen in FIG. 22, that allows for firm retention therein of any ofthe hooked ends 214 of the hooked arm members 216. Preferably, thebottom of the groove 212 is U-shaped, and of such a depth so that when ahooked end 214 is inserted therein, any rotation of the respectivehooked arm 216 will cause the end or tip 214' of the hooked end to abutagainst a portion of the interior wall 212', to thereby prevent thehooked end from escaping the groove, and, thereby, be firmly retainedtherein. In the preferred embodiment, the interior wall 212' is actuallyformed by the outer circumferential surface of the first, narrowersection 204, as seen in FIGS. 21 and 22. When viewing FIG. 22, therespective hooked arm 216 is allowed ample rotation in the clockwisedirection in order to allow for the lower, gripping end 216' thereof tobe adequately maneuvered place for gripping a fan blade, or the like,but counter-clockwise direction is limited by the contact of the tip214' of the hooked end against the juxtapositioned portion of theinterior wall 212' whereby during the use of the tool 200 for pullingoff a fan, or the like, the necessary take-up forces are providedbetween the housing section 206 and the hooked end 214. By utilizing acontinuous, 360-degree, annular groove, there is provided asubstantially infinite spacing capability for the plurality of hookedends 214 of the hooked arms. Thus, the only positions which the annulargroove 212 could not accommodate are those portions of the groovedirectly in-line with the bolts 226, since the bolts would interferewith the hanging of the hooked arms and their proper use. However, inthe case of the tool 200 where there are no bolts provided, or where thebolts 226 have been removed, then virtually an infinite spacingcapability between hooked ends and hooked arms may be achieved, wherebythe hooked arms 216 may be spaced apart those distances that suit theparticular job for which the pulling tool 200 is being used. Moreover,when the tool 200 is provided with bolts 226, the location of thesebolts relative to the lower edge 206' is not critical, since there areno equally-spaced holes required for the hooked ends 214, such as theholes 30 of the embodiment of FIG. 1. Thus, the bolts may be locatedmuch farther away from the lower edge 206', thereby providing a greaterdegree of telescoping of the lower housing section 206 over the partthat is to be gripped by the bolts 226 and pulled off thereby. Such anenhanced telescoping capability is advantageous for those parts that arestepped or have sections of different diameters.

Although it is preferred that the groove 212 be continuous for 360degrees, alternatively, the annular groove may be discontinuous, so asto provide a plurality of individual, separated, smaller groove-sections240, any one of which may receive therein a hooked end of a hooked arm,as shown in FIG. 23. In this modification, these smaller groove-sections240 are also preferably equally spaced about the upper, horizontalsurface of the lower circular cross-sectioned section of the housing,although their spacing may be staggered rather than equally-spaced. Thenumber of these smaller groove-sections may vary, and can be as few astwo, as shown in FIG. 23, or can, preferably be six, equallyspaced-apart groove-sections, the same number as the holes 30 in thetool of FIG. 1.

It is also possible to connect the two housing sections 202, 206 by afrustoconical transitional section, such as that shown in the otherembodiments, as long as there is provided an outer annular, steppedsurface portion for forming therein the annular groove 212.

While specific embodiments of the invention have been shown anddescribed, it is to be understood that numerous changes andmodifications may be made therein without departing from the scope,spirit and intent of the invention as set forth in the appended claims.

What is claimed is:
 1. In a pulling tool for pulling off a rotor of amotor or a fan from a shaft, said pulling tool comprising an elongatedscrew having a first end and a second end, a housing with which saidscrew is threadingly received, said housing comprising a first open endthrough which threadingly passes said screw, and a second open endthrough which protrudes said second end of said screw, said housingcomprising a first securing means for releasably holding a rotor of amotor, and second securing means for releasably holding a fan, saidfirst securing means comprising a plurality of rotatable bolts and afirst plurality of holes formed in said housing for threadinglyreceiving said plurality of bolts, and said second securing meanscomprising a plurality of hooked securing means, each said hookedsecuring means having a first end and a second hooked end, and a secondplurality of holes for removably mounting said hooked securing means,said second end of each said hooked securing means being capable ofbeing hung so as to protrude beyond said second open end of saidhousing, wherein the improvement comprises:said housing comprising atleast a first section having a circular cross section; said secondplurality of holes being formed in said circular cross-section section;said second plurality of holes being equally spaced about said section;said first plurality of holes and said second plurality of holes lyingon the same plane so that the first and second plurality of holes aresubstantially coplanar and substantially the same distance from saidsecond open end of said housing: each said hole of said first pluralityof holes being sandwiched between at least two said holes of said secondplurality of holes.
 2. The tool according to claim 1, wherein saidsecond plurality of holes comprises six holes spaced equidistantly apartabout the circumference of said circular cross-section section.
 3. Thetool according to claim 2, wherein said second securing means comprisesat least three arm-members with the first ends of said three arm-membersbeing removably mounted in three said holes of said second plurality ofholes, said three holes being alternate ones of said holes of saidsecond plurality of holes.
 4. The tool according to claim 2, whereinsaid first plurality of holes comprises three said holes spacedequidistantly apart about said circular cross section of said housing.